How do i get a VA refinance loan on a manufactured home?

Ok, there is a lot you are missing from this question.

Why do you want to refinance? Are you trying to buy the land the home is on or lower the interest rate?
Second note, your are your late husbands disability ratings have absolutely nothing to do with the process. If the loan is current, its based on your income and credit score when refinancing is considered.

I just refinanced a conventional mortgage with a VA loan. I had to pay the conventional for 6 months. Then re-fi. You may have to bring cash to close as VA has to appraise the dwelling and the appraisal impacts the amount they'll fund. Your lending institution loan officer should be able to explain this in your exact case. You can purchase a mobile/manufactured home on a VA Loan, so refi must also be possible. If the lender says they can't, go find another one. They can, they just won't. We went to three lenders before we found one.

Your disability rating may come in to play if there is a modification cost (grant program) and waiving certain fees. https://www.military.com/money/home-ownership/disabled-vets-can-expect-additional-benefits-from-their-va-loans.html

Your disability rating doesn't impact your access to a VA loan. Recommend you reach out to a local VA vet center or VSO Benefits Officer for assistance.